Diagnostic studies of molecular plasmas using mid-infrared semiconductor lasers

J. Röpcke, S. Welzel, N. Lang, F. Hempel, L. Gatilova, O. Guaitella, A. Rousseau, P.B. Davies

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)


Within the last decade mid-infrared absorption spectroscopy between 3 and 20 µm, known as infrared laser absorption spectroscopy (IRLAS) and based on tuneable semiconductor lasers, namely lead salt diode lasers, often called tuneable diode lasers (TDL), and quantum cascade lasers (QCL) has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, organo-silicon and boron compounds has lead to further applications of IRLAS because most of these compounds and their decomposition products are infrared active. IRLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species, which is of particular importance for the investigation of reaction kinetics. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of infrared spectroscopic techniques to industrial requirements. The recent development of QCLs offers an attractive new option for the monitoring and control of industrial plasma processes as well as for highly time-resolved studies on the kinetics of plasma processes.
Original languageEnglish
Pages (from-to)335-341
Number of pages7
JournalApplied Physics B: Lasers and Optics
Issue number3
Publication statusPublished - 2008


Dive into the research topics of 'Diagnostic studies of molecular plasmas using mid-infrared semiconductor lasers'. Together they form a unique fingerprint.

Cite this